Heating system



May 15H w. c. BUTTNER ET AL. 2,551,823

HEATING SYSTEM 2 Sheets-Sheet 1 Filed Feb. 10, 1945 c/F/W/W 1Q 5am;

ay 8 E951 w. c. BUTTNER ET AL 2,551,823

HEATING SYSTEM Filed Feb. 10, 1945 2 Sheets-Sheet 2 INV NTOR5.

Patented May 8, 1951 HEATING SYSTEM William C. Buttner, Winnetka, and Jerome R. Bunce, Chicago, Ill.

Application February 10, 1945, Serial No. 577,256

17 Claims.

The present invention relates generally to heating systems and more particularly to a space heatin arrangement for motor vehicles, trailers and compartments.

There are two general types of heaters for motor vehicles. One utilizes the heat developed in the engine as a source of heat, such as water radiators in circuit with the cooling system of the engine or hot air or steam radiators in heat exchange relationship with the exhaust gases from the engine. The other type converts fuel into heat independentl of, or in conjunction with the operation of the engine depending upon whether the intake manifold of the engine is used for creating the necessary draft or a separate blower Operating either as a compressor or suction device.

The present invention relate to the second or heat generating type of heater but differs materially from conventional heater of this type heretofore used in that it does not require a flame or an element producing a kindling temperature for the fuel to establish and maintain thermal conversion.

Furthermore, the invention is characterized by its ability to utilize, without change either a gasoline, such as used for the engine, or, any one of a. number of other fluid fuels available, such as alcohols, butane, propane, municipal gas, etc.

An object of the invention is to provide a heat generating heater for compartments in which the heat output can be varied infinitely over a wide range without danger of the heater going out or generating an explosive condition.

A further object of the invention resides in the relationship that air can be drawn through the heating coils of the heater to moderate the temperature generated therein and in surplus quantities to assure complete utilization of the thermal value of the fuel.

Although it is possible to utilize the partial vacuum developed in the intake manifold to induce a, draft when the engine is running, it is a further object of the invention to provide a rapidly starting heater which is self-sufficiently operative independently of engine operation.

A further object of the invention is the provision of a heat generating heater which generate heat and starts itself at temperatures without the use of flame or an incandescent element located in the path of the fuel which has caused explosion in conventional heaters.

A further object of the invention is to provide a heater which operates to generate heat from mixtures of fuel and air where the proportion of air is greater than that present with a mixture within the range of flame combustion for reasons of safety and greater efficiency in consumption of fuel.

Another object of the invention is to provide an improved heat radiator for motor vehicles, which is easily controlled, inexpensive to operate, efficient in its conversion of thermal properties of the fuel, and easily installed and maintained.

These being among the objects of the invention, other and further objects 'will appear from the drawings, the description relating thereto and the appended claims.

Referring to the drawings:

Fig. 1 is a fragmentary sectional view taken from the side of an automobile showing a preferred embodiment of the invention.

Fig. 2 is an enlarged vertical section through the heating system illustrated in Fig. 1.

Fig. 3 is a section taken upon line 33 in Fig. 2.

Fig. 4 is a vertical section taken upon the line 4@ in Fig. 3.

Fig. 5 is a schematic view of the preferred electrical circuit employed for operating the invention.

Fig. 6 is a fragmentary view illustrating a modified form of carburetion and carburetion control for the invention.

Fig. 7 is a plan view of the control panel for the invention as it appears upon the instrument panel of a motor vehicle,

Fig. 8 is a section taken upon the line 8-8 in Fig. 2, and

Fig. 9 is a view similar to Fig. 6 showing ,a further modification in which the fuel mixture can be changed by varying both the fuel and air.

In the present invention a catalyzer bed composed of catalytic agents such a compositions or elements of palladiumized or platinizcd material such as asbestos or a porous ceramic, platinum or palladium black, spongy platinum, nickel elements, or combination of any of these, is located in a flowing stream of air having a variable amount of vaporizable fuel or vapor fuel in it such as gasoline, butane, propane, alcohol, municipal gas, etc. Such catalytic agents are frequently described as primary adsorption catalysts for they operate to increase the reaction rate by adsorbing one or more of the reactant gases on their surface by primary valence forces which effect an activation or deforming of the molecules which makes them more susceptible to combine with the other reactants. The terms catalyst and catalytic agent as used herein are meant to include only such primary adsorption catalysts. A heater means is preferably located ahead of the bed to take the chill off of the flowing stream which has been cooled by vaporization of the fuel and to dry it, andthis heater means may be a portion of the exhaust manifold of an internal combustion engine, a resistance wire located inside a copper tube where it is sealed from direct contact with the stream, or a tube conducting hot exhaust gases from the engine in heat exchange relationship with the mixture. With the exhaust manifold connection the entire tream of fuel-air mixture is brought to a temperature high enough to complete vaporization without being appreciably chilled below 100 the latent heat of vaporization for a particular fuel being known. Eowever, this arrangement has the object that the engine must be started or running at the time. Wth the copper tube or other devices at least a portion of the stream is warmed enough to dry the mix.- ture so that the generation of heat or thermal reaction may take place in the catalyr 1' bed. Jvnh some fuels thermal reaction will take place without need for the vaporizing action of the heater means. Such fuels are gen rally those normally vapor at operating pressures if they are not chilled.

Draft is induced preferably by suction rather than pressure because with suction the fuel is induced to flow into the air stream, wiereas, if pressure is used the pressure opposes the introductic-n of the fuel unless the fuel is introduced ahead of the compressor, in which case certain dangers exist such as sparks being struck fro moving parts which might ignite certain limited portions of the fuel-air mixture where the proportions might be within the explosive range.

A separate source of fuel may prowhich is less volatile than the fuel supplied to the engine where airplane installations are considered if the gasoline supply is to be conserved, or, in event the vehicle is powered with Diesel oil. For t llS purpose any fuel whose lighter components vaporize at room temperatures will suffice al"hough natural gas, propane, butane, alcohol and gasoline are preferred in that order if available.

Referring now to the drawings in further detail, 9.- portion of an internal combustion engine it!- is shown located under the hood H in front of the dashboard E2 of a conventional automobile having a windshield l3 and an instrument panel The automobile is representative also of motor boats and airplanes. The engine it is provided with the usual air intake !5, carburetor l8, and intake and exhaust manifolds it and it. The carburetor is provided with a fuel well such as that indicated at 2-3 which is suplied with gasoline from a suitable source as from a storage tank (not shown) through a l leading either frpm a vacuum tank or in (not shown) By way of illustrating the preferred form of the invention, a radiator 22 made preferably of an aluminum casting is mounted upon the dash l2 beneath and forward of the instrument panel lil. As more particularly shown in Mg. 2, the radiator is provided with fins 23 disposed around a generally loop shaped passage having an outlet portion 25 flanged as at 25 to be bolted to a mounting plate 2? which is secured. in an opening upon the dash 52 by bolts Sll. inlet portion 35 of the passage 2c extends into and is disposed coaxial with the outlet 25. F; th inlet and outlet openin s open forwardly into engine compartment through the mounting plate 2'! and are preferably the lowest point in the radiator so that water condensation during idle 4 periods will run out of the radiator and not pen the bed.

The housing 32 may be mounted directly upon the radiator 22 although in its preferred form the same is mounted upon the flange 253 to be held in place by mounting bolts 33 threaded into the flange and tightened into place against lock washers 35.

Although the radiator passage 24 may be located in a horizontal plane it is preferred to it in a vertical plane with any one of a number of parallel passages (not shown) interconnecting the upper horizontal compartment 35 and the lower horizontal compartment The inlet 3! is in communication with the upper compartment 35 past a transverse tubular portion cast integrally wi h the radiator in which a heating or resistance wire 38 is mounted up insulating plugs (Fig. 8).

css had to the upper compartment which will herenafter be referred to as the reaction chamber, through a removable plug ii threaded into a boss 42, the opening closed by the plug 4| being of substantially the same diameter as the reaction chamber 35.

Within he reaction chamber disposed a Age catalyst bed 43 made of a metal screen envelope to filled with alternate layers of palladiumized asbestos 5 and screen separators made of brome wire of fine mesh. An asbestos bed i" nregnated with platinum or palladium black '1 wrapped in a fine mesh nickel screen has proven to be particularly successful and of long life.

iihenever the plug ti is removed, the catalyzcr bed a t can be removed and serviced or replaced if it becomes desirable to service the heater in event the catalyzer bed becomes poisoned or r -quires rejuvenation. [l groove in the end of the bed locates the bed with respect to the tube 3?.

A mixture of fuel and air is supplied to the inlet by means of a tube 47 flared as at $8 to teles e 0 er the mouth of the inlet Si and flanged at to receive elbow 5! threaded as at 52 upon 1; e outlet 25 to hold the tube s! in place.

t the outer end of the tube t? a suitable carburetor may be provided which preferably is set or controlled to supply a fuel-air mixture having a ratio that is outside of the limits of combustion. In the particular application the amount of air is greater than that required to support flame comb "ion. Such a carburetor is indicated at 53 which has a vaporizing bed 54 therein of copper wool held in place by a copper screening 55 below a nozzle located at the critical point of a venturi threat 5'! provided in the tube by inwardly upsetting the wall thereof.

Because of possible Underwriter Laboratory requirements, a flash arresting means such as a porous metal insert 29 known as Porex or screen v be located any place between the bed and the or as near to the catalyzer bed as posnicskel or T An air shield 58 guards against foreign matter falling into the carburetor and a needle valve 60, ilar yoke member 9 l, is

controlled r carturetor 53. The fuel a eading to th valve may be cont float bowl 2% of the carbi rotor 15 the engine shown in Fig. l or, to a separate source cf {LE1 supply as shown in S w rerein a t k 53 having a gauge 55 thereon and a filler cap is mounted in any suitable place to supply fuel 67 to the carburetor 53. If butane is supplied to the engine, connection can be made ahead of the demand regulator and the vaporizer bed dispensed with.

If gasoline is used in the engine, it is preferred to connect the fuel conduit 52 to the bowl of the engine carburetor unless as mentioned in airplanes it is desirable to conserve the gasoline for use in the engines. If not connected to the same source as the engine, the fuel supplied may be any one of a number of fuels enumerated, the bed mentioned working particularly well with gasoline, butane and alcohol.

The yoke control 6| leads to a handle 63 (Fig. 7) which also controls an on and off switch if! (Fig. 5) and a rheostat 1|.

To the outlet of the elbow 5! is connected the inlet passage 72 of a blower 13 which exhausts downwardly through an opening it to the atmos phere well below the engine compartment. The blower i3 is employed to induce a draft through the radiator and carburetor 53 by which air is drawn past the venturi 5! to pick up fuel admitted through the valve 60 and carry it through the bed 54 where evaporation and thorough homogenization is accomplished. From the evaporator 54 the fuel and air are advanced past the tube 37 which when heated by the resistance wire 38 will take the chill off of the fuel-air mixture incurred in vaporization and preferably warm the mixture to a temperature within the range of 150 to 200 F. to assure complete vaporization of the fuel. After the mixture has parted contact with the tube 3? it will pass into the catalyzer where the autogenous reaction takes place with an accompanying release of heat and hot gases to warm the radiator. What heat is not absorbed by the radiator in the upper passage Way will be carried by the hot gases through the lower passageway 35. From the lower passage the gases are drawn over the inlet to assist in warming the fuel-air mixture and then scavenged by the blower F3.

The blower i3 is preferably located at the outlet of the radiator 22 so that subatmospheric pressures created will, among other things mentioned, further assist in vaporizing the fuel in the air at the carburetor 53.

Referring to Fig. 6 an embodiment is shown for pre-warming the air against the chill of vaporization by means of the incoming air being drawn along the exhaust manifold iii of the engine through a sleeve held in place by a band 16. With this arrangement the tube 37 and heater wire 38 may be eliminated or used as desired, it being appreciated that the heater wire 38 is protected against direct contact with the incoming fuel-air mixture to avoid any danger of the wire igniting the mixture if by accident or unskilled adjustment of the device a fuelair mixture is supplied to the radiator in a ratio within the limits of combustion. A bare wire can be employed if it is so safeguarded by resistances and other controls that its temperature does not reach the kindling point of the fuel. Such a wire would be satisfactory from a safety viewpoint if it were not permitted to become any hotter than it would with a dull red glow.

Referring to Fig. 9 another form of carburetor is illustrated in which a container 63a is provided with a gauze or blanket B9 soaked with the fuel. A part of the air is drawn through the blanket for saturation with the fuel and the other part of air is drawn through a by-pass with a valve 59 regulating the proportions in a way comparable to the valve 60.

A thermo-sensitive bimetal strip H is mounted outside and upon the wall of the upper chamber 35 where it is subjected to the heat developed in the reaction chamber 43. The bimetal strip serves as the moving pole between two electrical contacts 19 and 8B, the one 19 of which is engaged when the bimetal is cold and controlling the electrical current to the resistance wire 38 in series with the switch 10. With this arrangement electricity is supplied by the battery 18 to energize the resistance coil 38 whenever the witch Ill is closed and the bimetal strip His cold. The other contact is engaged by the bimetal strip ll when it is warm. Engagement with the contact 8|] places a blower 8! in operation which, as shown in Fig. 3, draws in air over the radiator and drives it out into the occupant compartment. This air is drawn in through elongated openings 82 stamped in the housing 32 which openings extend parallel with the upper and lower passages 35 and 36 of the radiator. The blower 8! can be started at the same time as the heater if desired because the cooling effect thereof is negligible as far as the reaction is concerned.

Beyond the openings 82, as shown by arrows 83, the air passes between and in heat exchange relationship with the fins 23 to the inlet opening 84 of the blower. The cage of the blower is made up of two substantially identical elements 85 as shown in Fig. 4 having openings which make up with close clearance with the circumference of blades 89 of the blower, the elements 85 being arranged to be held in place between the radiator portion 86 of the housing 32 and the motor compartment portion 8! of the housing 32. Bolts 88 are employed to hold these elements in assembled relationship and the housing walls of the two portions 86 and iii are stamped to provide suitable grooves for holding these elements in correct position where they will cooperate with the blower blades 89 properly without danger of the blades striking them.

The upper end of the upper one of the elements 85 is provided with a butterfly valve Qil controlled from the instrument panel by a flexible cable 9| operated by a handle 32 (Fig. 1) and the outlet thereof is bifurcated as at 93 for connection with suitable conduits 94 leading to the defroster slots 95 opening upwardly behind the windshield l3. Movement of the butterfly valve controls the amount of air driven by the vanes 89 into the upper element for defrosting purposes. If completely closed, the vanes 89 merely cavitate with respect to the upper element and deliver the air to the lower one of the two elements 85. A nozzle is swiveled to the lower end of the lower element as at 8! and pivoted for movement up and down as at 38. The mouth of the nozzle as viewed in Fig. 3 is flared and provided with deflectors H10 to fan out the air stream and direct it either downwardly against the floor of the vehicle or horizontally towards the seats of the automobile depending upon its elevation, and, to one side of the car or the other depending upon its swiveled position.

Vanes 89 of the blower are divided into two effective blower portions, the one if)! drawing the air over the radiator and the other, I232, moving air from the motor compartment 8'! of the housing 32 into the members 85 through an opening Hi3. Air can enter the motor compartment either from the engine compartment of the automobile if outside air is desired, or through a vent I04 controlled by a handle I35 if air already in the compartment is to be recirculated without contact with the radiator 22. This air serves to keep the motor GI and compartment 81 quite cool. The motor 8! is mounted within the housing portion 8'! upon brackets I05 in a suitable manner as by bolts.

In operation the handle 68 is located in an off position which is the position of the contacts as illustrated in 5. As the handle 68 is moved to low position, engagement is had with the contact NJ to close the battery circuit through the resistance wire 38 and bimetal strip T? as already described. At the same time that this engagement is established the switch also engages the rheostat ll to start the blower l3 and create a draft through the radiator as already described. Further movement of the handle to the right will operate to open the valve 55) which is provided with a left hand thread for this purpose and fuel will begin to flow to the nozzle of the carburetor 53 to be picked up by air moved by the blower 2'3. After the air and fuel mix in the evaporation bed 54, the tube 37 shielding the resistance wire 33 from direct contact with the fuel will become warm and the fuel-air mixture flowing across it will be dried and vaporization assured. From contact with the tube the mixture will flow into the catalyzer bed to start the reaction between the fuel and air in the presence of the catalyzer to liberate heat. This heat will be absorbed in the radiator walls until such time that the bimetal "ii is warmed. Thereupon the bimctal breaks engagement with the contact '19 and moves into engagement with the contact 80 to start the blower 8i Thereafter any setting of the handle 68 between the low and high position upon the dial will determine the heat output of the device, and such setting will be made according to the comiort 01" the occupants.

In certain installations it may be desirable to have a constant draft-volume of air induced by the blower '13 in which case the blower i3 is connected in series with the contact 80 and the air fiow through the carburetor 53 is maintained constant by a restricting orifice of predetermined size. With this arrangement the only thing that requires adjustment to vary the heat output of the heater is the amount of fuel inducted into the stream of flowing air. In either event it is desirable for safety reasons to adjust the fuel and air ratio to exceed the limits of combustion so that there will be little, if any, danger of explosion in the radiator.

The catalyzer will convert iuel present in the air into heat regardless of the fuel-air ratio. This conversion takes place without the flame, generally referred to in conventional gasoline heaters as combustion, and in most instances the temperatures will be well below the kindling point of the fuel whereby the heat output of the device is not only mild and adequate but can be varied infinitely between warm and hot without going out merely by adjusting the amount of fuel that is supplied to the air considering also the moderating eiiect present with any excess amounts of air that mi ht have been passing through the catalyzer bed.

For those installations where a high concentration of heat is desired at the start or constantly, the present invention can be adjusted to supply a fuel-air mixture within the limits of combustion in which case the heat generated in the catalyzer bed will approach or exceed the kindling temperature of the fuel. In such installations the embodiment can be provided with a flash arrester between the tube 31 and the catalyzer bed i3 to prevent possible flash backs. Under these circumstances with the incoming mixture warmed to complete vaporization and dry it, the mixture will react in the presence of the catalyzer without being cooled by extra air passing through the radiator. Thus the present invention can be adapted to provide high heat if desired although in its use for passenger vehicles its arrangement for moderate heat without danger of explosion is preferred.

Having thus described the invention, several modifications and possible constructions, it will be readily apparent to those skilled in the art that various and further changes can be made without departing from the spirit of the invention, the scope of which is commensurate with the appended claims.

What is claimed is:

l. A heater of the class described for motor vehicles including a radiator unit having the inlet and outlet thereof in heat exchange relationship through a common wall, means for generating heat in the radiator comprising a primary adsorption catalyst bed, means for supplying a fuel-air mixture to the bed through the inlet, said mixture being warmed and dried by warm gases leaving the outlet of the radiator.

2. A heater of the class described for motor vehicles having a compartment wall including a radiator unit having coaxial inlet and outlet conduits in heat exchange relationship through a common wall, means for mounting the radiator on the compartment wall including said conduits, a primary adsorption catalyst for generating heat in the radiator, means upon the compartment side of the compartment wall for circulating air over said radiator, and means upon the other side of the compartment wall for supplying a fuel-air mixture to the generating means through the inlet to be warmed by warm gases leaving the outlet of the radiator.

3. In a motor vehicle having a riding compartment and an engine compartment separated by a wall, the combination of a radiator disposed in heat exchange relationship with the air in the riding compartment, a reaction chamber in the radiator, a primary adsorption catalyst in the reaction chamber, means for supplying a fuelair mixture, means for warming said mixture, and means in the engine compartment for drawing said warmed mixture into the reaction chamber.

4. In a motor vehicle having a riding compart ment and an engine compartment separated by a wall, the combination of a radiator disposed in heat exchange relationship with the air in the riding compartment, means for circulating air in the riding compartment over the radiator, a reaction chamber in the radiator, a primary adsorption catalyst in the reaction chamber, means for supplying a fuel-air vapor mixture, means for warming said mixture, and means in the engine compartment for drawing said warmed mixture into the reaction chamber in contact with the catalyst to liberate heat to the radiator.

5. In a motor vehicle having a riding compartment, the combination of a reaction chamber, a primary adsorption catalyst in the reaction chamber, carburetor means for mixing fuel and air, means for moving the fuel-air mixture through said chamber over the catalyst to liberate heat, means for dissipating the liberated heat in the riding compartment, and means for vary- 9 ing the proportions of fuel and air beyond the limits of flame combustion.

6. In a motor vehicle having a riding compartment, the combination of a radiator having a reaction chamber, a primary adsorption catalyst in the reaction chamber, carburetor means for mixing a vaporizable fuel and air, means for moving the fuel-air mixture through said chamber over the catalyst to liberate heat to the radiator, means for dissipating in the riding compartment the heat received by the radiator, and means for varying the proportions of fuel and air beyond the limits of flame combustion.

7. A heater of the class described for motor vehicles Comprising a radiator having a passage therethrough, a primary adsorption catalyst bed disposed in passage means for mounting the radiator on one side of a substantially vertical wall of the vehicle body, means for generating hot gases for movement through said radiator passage, the outlet of said passage being the lowest point of the passage whereby condensation during resting periods of the heater will drain from the radiator.

8. The combination with a motor vehicle having a riding compartment and Wall, a radiator having an inlet and outlet at the lowest point in the radiator and in heat exchange relationship With each other, means for mounting said radiator with said inlet and outlet through a single hole in the wall, means for supplying the inlet with a mixture of a vaporizable fuel and air, means including a primary adsorption catalyst bed for liberating heat in the radiator from the fuel-air mixture, means for establishing a draft for the fuel-air mixture to move it through the radiator and means for circulating the air in the riding compartment over the radiator.

9. A heater of the class described comprising a space heating radiator, means for forming a nonignitable mixture of air and a vaporizable fuel, a primary adsorption catalyzer bed, means of communication between the mixing means radiator and catalyzer bed, and means for propelling the mixture of air and fuel through the communication means and over the catalyzer bed, said fuel and air reacting upon the catalyzer bed to liberate heat to the radiator.

10. A heater of the class described comprising a space heating radiator, means for mixing air and a vaporizable fuel, a primary adsorption catalyzer bed, means of communication between the mixing means radiator and catalyzer bed, means for propelling a mixture of air and fuel through the communication means and over the catalyzer bed, said fuel and air reacting upon the catalyzer bed to liberate heat to the radiator, and means for varying the ratio of fuel and air present in the mixture from a lean nonignitable mixture to a relatively rich ignitable mixture during operation of the heater.

11. A heater of the class described comprising a space heating radiator mounted for communication with the riding compartment of a motor vehicle, means for mixing air and a vaporizable fuel, a primary adsorption catalyzer bed, means of communication between the mixing means radiator and catalyzer bed, means for propelling the mixture of air and fuel through the communication means and over the catalyzer bed, means for homogenizing and drying said fuel air mixture before contacting the catalyzer bed, said fuel and air reacting upon the catalyzer under conditions of flameless combustion to liberate heat to the radiator.

12. A heater of the class described comprising a space heating radiator, means for mixing air and a vaporizable fuel, an asbestos bed coated with platinum black in the radiator, means of communication between the mixing means and radiator, means for propelling a mixture of air and fuel through the communication means and over the asbestos bed, means for circulating air over the radiator, means for warming the fuel air mixture entering the radiator to dry it, said fuel and air reacting upon the coated asbestos bed without ignition to liberate heat to the radiator.

13. A heater of the class described comprising a space heating radiator, means for mixing air and a vaporizable fuel in proportions beyond the limits of flame combustion, an asbestos bed coated with primary adsorption catalytic material, means of communication between the mixing means radiator and asbestos bed, and means for establishing a draft for the mixture of air and fuel through the communication means and over the catalyzer bed, said fuel and air reacting below the ignition temperature upon the asbestos bed to liberate heat to the radiator, and means for varying the proportions of fuel and air in said mixture.

14. The method of heating a metal radiator comprising mixing a volatile fuel and air in proportions beyond the range of flame combustion, reacting the fuel and air upon a primary adsorption catalyst bed under forced draft to liberate heat and heat said bed, conducting heat from said bed directly to said metal radiator to heat said radiator, and conducting the products of said reaction away from said bed to the atmosphere.

15. The method of heating a radiator comprising forming a stream of a vaporizable fuel and air in proportions beyond the range of flame combustion, conducting the stream. over a primary adsorption catalyst bed in direct contact with said radiator to liberate heat and heat said bed, conducting the heat from said bed to said radiator, conducting the products of the reaction in close proximity to said stream prior to its entering said bed to preheat and dry said stream, and discharging the products to the atmosphere.

16. The method of heating a radiator comprising mixing a vaporizable fuel and warmed air in proportions wherein a mixture is supplied which is too lean to support flame combustion, reacting the fuel and air upon a primary adsorption catalyzer bed under forced draft and subatmospheric pressure to liberate heat, absorbing liberated heat by said radiator, and confining the flow of the by-products of the reaction for discharge to the atmosphere at a point remote from said radiator.

17. A heater of the class described comprising a space heating radiator, means for forming a nonignitable mixture of air and a vaporizable fuel, a catalyzer bed, said bed comprising a finely divided primary adsorption catalyst, means of communication between the mixing means radiator and catalyzer bed, and means for propelling the mixture of air and fuel through the communication means and over the catalyzer bed, said fuel and air reacting upon the catalyzer bed to liberate heat to the radiator.

WILLIAM C. BUTTNER. JEROME R. BUNCE. I

(References on following page) 11 12 REFERENCES CITED FOREIGN PATENTS The following references are of record in the Number Country Date file of this patent: 469,515 Great Britain July 27, 1937 UNITED STATES PATENTS 5 OTHER REFERENCES Number Name Date Surface Combustion and its Industrial Appli- 1,880,178 Krause Sept. 27, 1932 cation, Jom'nal of Gas Lighting, April 4, and 1,923,614 Clarkson Aug. 22, 1933 April 11, 1911, 2,165,269 Karsel July 11, 1939 Handbook of Chemistry and Physics, 25th edi- 2,188,133 Hepburn Jan. 23, 1940 10 tion, p. 2164 (Chemical Rubber Publishing Com- 2,308,88'7 McCollum Jan. 19, 1943 pany, Cleveland, Ohio). 2,321,940 Robertson June 15, 1943 2,332,094 McCollum Oct. 19, 1943 2,379,017 McCollum June 26, 1945 2,391,447 Edge Dec. 25, 1945 i5 

